TY - JOUR
T1 - Backarc basin inversion and subcontinental mantle emplacement in the crust
T2 - Kilometre-scale folding and shearing at the base of the proto-alborán lithospheric mantle (Betic Cordillera, southern Spain)
AU - Hidas, Károly
AU - Booth-Rea, Guillermo
AU - Garrido, Carlos J.
AU - Martínez-Martínez, José Miguel
AU - Padrón-Navarta, José Alberto
AU - Konc, Zoltán
AU - Giaconia, Flavio
AU - Frets, Erwin
AU - Marchesi, Claudio
PY - 2013/1
Y1 - 2013/1
N2 - To constrain the latest evolutionary stages and mechanisms of exhumation and emplacement of subcontinental peridotites in the westernmost Mediterranean, we present here a detailed structural study of the transition from granular spinel peridotite to plagioclase tectonite in the western Ronda Peridotite (Betic Cordillera, southern Spain). We show that the plagioclase tectonite foliation represents an axial surface particularly well developed in the reverse limb of a downward facing moderately plunging and moderately inclined synform at the base of the Ronda massif. The fold limbs are cut by several mylonitic and ultramylonitic shear zones with top-to-the-SW sense of shear. After restoring the middle to late Miocene vertical-axis palaeomag-netic rotation and the early Miocene tectonic tilting of the massif, these studied structures record southward-directed kinematics. We propose a geodynamic model in which folding and shearing of an attenuated mantle lithosphere occurred by backarc basin inversion during late Oligocene (23-25 Ma) southward collision of the Alboran Domain with the palaeo-Maghrebian passive margin, leading to the intracrustal emplacement of peridotites in the earliest Miocene (21-23 Ma).
AB - To constrain the latest evolutionary stages and mechanisms of exhumation and emplacement of subcontinental peridotites in the westernmost Mediterranean, we present here a detailed structural study of the transition from granular spinel peridotite to plagioclase tectonite in the western Ronda Peridotite (Betic Cordillera, southern Spain). We show that the plagioclase tectonite foliation represents an axial surface particularly well developed in the reverse limb of a downward facing moderately plunging and moderately inclined synform at the base of the Ronda massif. The fold limbs are cut by several mylonitic and ultramylonitic shear zones with top-to-the-SW sense of shear. After restoring the middle to late Miocene vertical-axis palaeomag-netic rotation and the early Miocene tectonic tilting of the massif, these studied structures record southward-directed kinematics. We propose a geodynamic model in which folding and shearing of an attenuated mantle lithosphere occurred by backarc basin inversion during late Oligocene (23-25 Ma) southward collision of the Alboran Domain with the palaeo-Maghrebian passive margin, leading to the intracrustal emplacement of peridotites in the earliest Miocene (21-23 Ma).
UR - http://www.scopus.com/inward/record.url?scp=84871898811&partnerID=8YFLogxK
U2 - 10.1144/jgs2011-151
DO - 10.1144/jgs2011-151
M3 - Article
SN - 0016-7649
VL - 170
SP - 47
EP - 55
JO - Journal of the Geological Society
JF - Journal of the Geological Society
IS - 1
ER -